The highly reactive, i.e., pyrophoric, nature of lithium metal, particularly high surface area lithium metal powder, can be a deterrent for its use in a variety of applications. Thus lithium metal is typically in a stabilized form. It is known to stabilize lithium metal powder by passivating the metal powder surface with CO2 such as described in U.S. Pat. Nos. 5,567,474, 5,776,369, and 5,976,403, the disclosures of which are incorporated herein in their entireties by reference. The CO2 passivated lithium metal powder, however, can be used only in air with low moisture levels for a limited period of time before the lithium metal content decays because of the reaction of the lithium metal and air.
Another option has been to coat the lithium powder with a protective layer. For example, U.S. Pat. No. 6,911,280B1 proposes coating with an alkali or alkaline earth metal carbonate. U.S. Pat. No. 4,503,088 proposes coating an epoxy resin on a lithium negative electrode as a passivation layer. U.S. Pat. Nos. 5,342,710 and 5,487,959 propose using a complex of I2 and poly-2-vinylpyridine as a passivation layer. These suggested protective layers; however, often result in a decrease in conductivity and weak mechanical strength.